The present invention relates to a semiconductor device, and more particularly, to a semiconductor device providing a reliable data valid window.
A semiconductor memory device generates an internal voltage having a stable voltage level by using an external voltage supplied from an external circuit in order to perform a reliable operation. However, the voltage levels of the internal voltage and the external voltage are easily decreased in a practical read operation of the semiconductor device because of the abrupt current consumption. Due to the abovementioned decrease of the internal voltage, a read operation error can be induced.
In detail, several internal circuits, e.g., a sense amplifier, a pre-driver, and an output driver, which are located in a read path of the semiconductor device, are operated sequentially in response to a read command. In the operation of the internal circuits, the current consumption is abruptly increased. Particularly, an amount of the current is consumed during a period of an initial data output, and therefore, the voltage is decreased mostly in this period. As a result, an initial data valid window becomes relatively narrow because of the abrupt current consumption and the semiconductor device fails to perform an initial read operation correctly.